This invention relates to an improvement in electric swivel head hand lanterns. These lanterns have been well-known for quite a number of years and are very useful, as they combine a powerful and long-lasting battery with a large lamp to produce a light source.
An electric swivel head hand lantern is generally comprised of three basic elements; a heavy duty lantern battery, a handle which fits over and attaches to the top of the battery and a swivel head which is connected to the upper portion of the front of the handle. The swivel head contains the lamp.
Although the entire lantern itself is heavy and unwieldy, primarily due to the weight of the battery, the mobility problem is overcome by the swivel head feature which permits the direction of the light beam to be changed without changing the position of the handle and the battery. This is accomplished because the swivel head can pivot about its connection point with the handle in a vertical plane. Most swivel heads are capable of directing a beam at any angle in approximately a 120 degree arc starting from a vertical position. This swivel head feature enables the operator to direct the light beam upward or downward while holding the lantern handle and attached battery in a comfortable level position and, therefore, it is unnecessary to actually point the entire lantern in the desired direction.
Furthermore, in addition to being more powerful than an ordinary flashlight, these lanterns are also much more versatile. They can be set on the ground or any relatively flat surface and the light beam positioned at the desired angle. The beam will remain properly directed while the lantern is unattended, and the operator thereby has both his hands free to do any required work in a now well-lighted area.
Because of their powerful, long-lasting beam and their versatility, these lanterns are widely used by police and fire departments. Therefore, due to the emergency nature of much of their use by these agencies, lantern reliability and durability is of prime importance. However, the dependability of existing swivel head lanterns is not great, primarily due to their extensive electrical wiring. Furthermore, the wiring creates additional problems in manufacturing these devices which substantially increases the cost of manufacturing the lantern, and thereby substantially increases the ultimate retail cost of the devices to the consumer.
A general uniformity is found in the structural arrangement and dimensions of these lanterns which is due, at least in part, to the usual method of connecting the standard lantern battery which has two screw threaded terminal posts in its top surface. The lantern handle fits over the top of the battery and the terminal posts protrude through two terminal post holes in the base of the lantern handle. Since the corresponding screw threaded terminal caps for the terminal posts are larger than the holes in the handle base, the battery becomes firmly attached to the lantern when these caps are screwed on to the protruding terminal posts and tightened. As this type of battery is a standard one in the battery industry, usually of about 6 volts, this manner of attachment permits quick and easy battery replacement, and the lanterns all employ a common type of power source.
This arrangement, however, has created an inherent problem in prior lanterns, as the terminal post holes in the lantern handle must be wired to make contact with the battery posts. This usually requires wiring a metal contact ring for the post hole. If the handle is metallic, as it often is, a nonconductive washer must surround the contact ring to insulate the ring from the handle and prevent the battery from being shorted out. This insulating washer must be riveted to the handle.
The wiring from the battery post contacts are then run up to the crosspiece of the lantern handle where the switches are usually located. Most swivel head lantern switches are of the slide type which use movable strips of metal to open and close contacts. The wiring from the battery post contacts must be riveted, soldered or crimped inside the crosspiece of the handle to the metal slides of the switch.
In order to provide electrical power to the lamp in the swivel head, additional wires must also be attached inside the handle to the switch contacts and run from the switches to the swivel head. As most of these types of lanterns are designed to permit as much freedom of movement for the swivel head as possible, there is usually a gap between the handle and the swivel head so the handle will not restrict the swing of the swivel head. Thus, these electrical wires from the switch in the handle must be run across this open space and are, therefore, exposed. When these wires are inside the swivel head they are usually crimped with a type of terminal ending, such as a slotted eye bolt, which can be attached to and removed from the lamp.
In addition to this fundamental wiring, most lanterns have a secondary red flasher light at the end of the handle opposite the swivel head which also requires the wiring of a separate switch in the same manner as previously described.
Because of this fairly extensive wiring, manufacture of these prior lanterns is expensive, as machine operations, such as riveting, and time consuming manual operations, such as hand wiring, soldering, wire crimping and sleeving must be performed, all of which combine to raise the cost of manufacture substantially.
In addition, these manufacturing expenses are further increased because of removable wiring connections required in the swivel head. Swivel head lanterns generally use one of two types of lamps; either a single bulb and reflector or a sealed beam lamp. If a bulb and reflector are used, the wires inside the swivel head which come from the handle and the battery must be manually connected to the outer casing of the bulb and the base of the bulb respectively. If a sealed beam lamp is used, one of these wires must be manually connected to each of the two contact bars on the base of the lamp. At this point, the bulb and reflector or the sealed beam lamp must be balanced on the lip of the swivel head bowl while a retaining ring or other device is attached which holds the connected lamp assembly in place. This operation is time consuming and only done with a good deal of difficulty. Furthermore, the lantern owner must repeat this operation whenever the bulb or lamp needs replacement.
In addition, because of this prior manner of lamp attachment, there is always an inherent possibility of a disconnected wire or at least poor electrical contact inside the swivel head itself every time a lamp is installed. Most known lamps are produced with only a small raised bump at one point on the back edge of the lamp. Since there is usually only a minor indentation, if any at all, in the lip of the swivel head bowl to seat the raised bump on the lamp, the lamp has a great tendency to rotate as the retaining collar is screwed on. The rotation of the lamp will cause a corresponding rotation in the wires inside the swivel head bowl which are attached to the lamp, and the twisting of these wires may loosen or break the electrical connections.
Besides being expensive to manufacture, the prior swivel head lanterns have another major drawback. As with any piece of electrical equipment, the wiring and wiring connections are likely to loosen or break completely with any type of rough use, and these lanterns are often given the severest type of treatment, particularly in an emergency situation when dependability is of paramount importance. Furthermore, those lantern wires which are exposed between the swivel head and the handle are particularly susceptible to breakage, as they are often under stress and likely to be stretched or pinched when the swivel head is moved.
Nevertheless, despite the high cost, and lack of reliability, these lanterns are popular and widely used.